An activist whose petition earlier this year triggered a Tanzanian high court ruling against child marriage said social transformation was needed to end the longstanding custom many families use as a “survival system.”

“Changing the law is not the ultimate end to child marriage,” said Rebeca Gyumi, founder of the Msichana Initiative, a Tanzanian charity promoting girls’ rights. “Changing mindsets and trying to trigger the shift of customs and traditions is the next thing we are planning to do,” she told the Thomson Reuters Foundation in London.

The High Court of Tanzania ruled in July that two sections of the 1971 Marriage Act, which allow girls to marry at 15 with parental consent and at 14 with the permission of a court, were unconstitutional.

The landmark ruling, effectively raising the legal age of marriage for girls to 18, was made in response to a petition by Gyumi who argued that the act violated girls’ rights to equality, dignity and access to education, as granted by the constitution.

Attitudes must change

The real challenge is to shift attitudes in communities where parents marry off their daughters so their sons can to go to school or to ease the economic burden on their families, Gyumi said.

“The issue is deep-rooted in a male-dominated, patriarchal system where a girl child is not really treated as an equal person,” she said in an interview.

She described child marriage as “a sort of a survival system” in a society where poverty is entrenched. “Sometimes parents see marrying their kids as the only solution to the issues they have,” she added.

Tanzania has one of the highest rates of child marriage globally, with nearly 2 in 5 girls getting married before their 18th birthday, according to campaign group Girls Not Brides. It says the practice is particularly prevalent in rural areas where girls as young as 11 are married.

Child marriage deprives girls of education and opportunities, and puts them at risk of serious injury or death if they have children before their bodies are ready. They are also more vulnerable to domestic and sexual violence.

Gyumi said if Tanzania capitalized on the momentum of the ruling, in 20 to 30 years it should be possible to reduce the number of girls being married off early.

Men must be involved

“We have to change the story from Tanzania being among the countries with the highest percentage of child marriages to being the country that really tries to solve the issue by changing the law and educating the community,” she said.

Gyumi said men’s involvement was essential for the campaign against child marriage to be successful.

“Sometimes it’s not just about what you’re saying but who is saying it. Women alone can’t win this war.” Each year more than 15 million girls worldwide are married before they turn 18, Girls Not Brides says.

In June, the U.N. Human Rights Council adopted a resolution calling for an end to child, early and forced marriage, and recognizing child marriage as a violation of human rights.

Ending child marriage by 2030 is one of the targets contained in the new Sustainable Development Goals adopted by world leaders at a U.N. summit last year.